The flow of the skimmer pump is rated at 1850 litre per hour, at no head pressure. Thats not the skimmer rating for your system volume.RiaanP the skimmer is rated for 1850l/h and irie ivan had that coral for a month now
As air is mixed in, the water flowing through it is reduced, which is a good thing.
As a rough estimate, skimmers are more or kess rated for tank volume according to the volume of air they pull in an hour, not the water pushed through them.
Notwithstanding, you seems to be off to a good start, and have some nice corals there.